The ability of a player to hit a golf ball properly is largely dependent upon the path of the golf club during the swing. Although the styles of expert players may vary widely, the basic motion of their golf clubs during their swing is strikingly similar. The concept of prior art devices is to control the motion of the golf club to emulate that of an expert player.
A novice by repeatedly practicing his swing on a trainer learns the "feel" of a proper golf swing. The effectiveness of these training devices is dependent on their ability to simulate actual playing conditions. The more life-like the practice swing, the more likely the player can duplicate the swing while using a golf club under real playing conditions.
The prior art training devices use a number of different means for controlling the golf club. There are two basic types of devices. The control is maintained by connecting the device to the golf club by either 1) the head of the golf club or 2) the shaft of the golf club. The key to the feel of the swing is the mechanism that controls the rotation of the golf club.
A key deficiency of all of the prior art is the limit placed on the variation of the plane of the swing. The prior art devices such as U.S. Pat. No. 2,448,904 to S.A. Millner, force the player to use the same swing plane for both the back and forward swings. The use of a single plane incorrectly emulates the actual golf swing, which in contrast uses different swing planes for the back and forward swings and also both swings are elliptical rather than circular.